1. Field of the Invention
Apparatuses consistent with the present invention relate to a fast Fourier transform (FFT) operation circuit used in digital signal processing of data communication, video and voice signals.
2. Description of the Related Art
A fast Fourier transform (FFT) is used for extracting a frequency component hidden as data in a series of signals in the time domain, and is capable of processing a plurality of data signals in a short time. The FFT also has an advantage in that it requires only a small circuitry area when it is implemented as hardware.
In wireless communication standards, such as those used for mobile phones, a variety of cellular methods or wireless local area network (WLAN) methods are used. Ordinary users utilize the advantages of these standards, thereby trying to perform efficient wireless communication. For example, in the field of data communication, the length of FFT data (FFT length) varies with respect to the purpose of its use. Examples include Institute of Electrical and Electronics Engineers (IEEE) 802.11a which is a WLAN standard, in which the data length is 64, and one of 4 Generation (4G) mobile standards in which the data length is 1023. Accordingly, a multi-mode terminal which implements a plurality of standards in one hardware apparatus has a plurality of embedded chip sets, thereby increasing the size of the apparatus. As a result, the necessity of an FFT operation circuit for a plurality of chipsets capable of handling a variety of standards has been recognized.
A related art FFT-dedicated processor has a plurality of operation circuits corresponding to a plurality of radices in circuits for processing FFT operations, in which an operation circuit corresponding to a radix in each FFT operation stage is selected and used. Accordingly, since the FFT dedicated processor has many operation circuits corresponding to radices, circuits are large and the processor consumes a lot of power.